Process of concentrating columbium minerals by froth flotation



March 1959 A. w. LAST ET AL A PROCESS: OF CONCENTRATING COLUMBIUM MINERALS BY FROTH FLOTATION Filed 001;. 10. 1957 NIoBIuNI 0R l -AQUEOUS PULP T ?;%IF OPTIONAI. f T0 WASTE TAILINGS I A SLIMES A DESLIMING OPTIONAI. F I To WASTE sA Ds k MICA AND IRON MlCA AND IRON SULFIDE SULFIDES FROTH CONCENTRATES OPTIONAL FLOTATIQN TO WASTE TAIL INGS MAONE'TITE MAGNETIC SEPARATION OPTIONAL I TO WASTE I AQUEOUS PU l P w F I FILTER rFlLTRATE TO WASTE I CAKE i F REPULPING l AQUEOUS PULP BURNER OlL-- 1 --a-QuINOI INOI FROTH FLOTATION I I NIOBIUMI-BEARING TAILINGS FROTH FFILTERJ FFILTERJ l l CAKE CAKE FILTRATE FILTRATE (B-QUINOLINOL) (B-QUINOLINOL) NlOBlUM MINERAL CONCENTRATE WASTE IN V EN TOR.

- ARTHUR W. LAST KENT E MARQUARDSON titanium minerals.

Un t W8. 0

PROCESS OF CONCENTRATING COLUMBIUM MINERALS BY FROTH FLOTATION Arthur W. Last and Kent F. Marquardson, SaltLake City, Utah, assignors to Kennecott CopperCorporation, New York, N. Y., a corporation of New York Application October 10, 1957, Serial No. 689,435

14 Claims. (Cl. 209-166) This invention relates to the art of froth flotation for the selective recovery of specific minerals from their ores. It has particular reference to the recovery of columbium minerals from the ores in which they are found.

The metallic element niobium, or columbium as it is commonly called by metallurgists, has been known well over'a hundred years.

forms. 7 g n r There are vast deposits of columbium oresthat have been left 'unworked for the lack of any effective and economical process for separating the valuable'minerals from the ganguematerials with which they are associated in the natural ore deposits. Certain ores containing the mineral columbite are being worked in instances where separation of the columbite by gravity means,

It occurs in various mineral Another feature useful in minimizing reagent consumption is the reclaiming of the reagent-bearing solution from the final flotation pulp, and the use of same in preparing the initial flotation pulp for a subsequent run. This is advantageously done in connection with still another feature of the invention, namely, preliminary treatment of the ore for the elimination of various gangue ment for gangue elimination is dewatered. It is then re-pulped in recovered reagent-bearing solution prior to undergoing the significant froth flotation stage of the process.

" Further objects and features of the invention will become apparent as the description proceeds with respect to specific procedures and test results.

electrostatic means, or by magnetic means has proven economicallyfeasible. However, such separation procedures have not been economical in their application to ores containing other columbium minerals, such as py rochlore, perovskite, niocalite, betafite, etc.

No successful flotation process has to our-knowledge yet been reported for the selective flotation and recovery of colu'mbium minerals. There has hitherto been no known reagent capable of floating suchminerals on a selective basis. 7 V g n 7 We have found that columbium minerals may be effectively and economically floated from "gangue constituents of an ore by the use of a reagent selected from a. particular group of chemical compounds, serving as' a collector selective to such columbium minerals. The group of chemical compounds consists of a hydroxyquinoline, specifically, 8-quinolinol, commonly known as oxine, and mono-lower-alkyl-substituted 8-quinolinols.

While 8-quinolinol is well known as a chemical com pound, it is normally used in highly purified form in the chemical art as an analytical reagent. The only instances where 8-quinolinol has even been triedas a flotation reagent is in connection with certain academic investigations concerned with abstract flotationtheory. In such instances, the materials involved were merely artificial mixtures containing solely zinc, iron, tungsten, and Such experiments have evoked little interest, and have given no indication that the particular reagent has any eifectiveness as applied to columbium.

;In accordance with the present invention, the ore is finely ground in a manner customary in conventional flotation practice, and is subjected to agitation and aeration, as an aqueous pulp, in the presence of the particular reagent specified. The columbium minerals are effectively collected in the froth,- to yield a columbium concentrate.

A principal object of the present invention is to provide a froth flotation process whereby columbium minerals may be effectively recovered from their ores on a selective basis as respects other constituents'of such ores. Another object is to minimize reagent. consumption and expense,

Our work has shown that 8-quinolinol (C H NO) having the formula:

(8)2201; N 1 110 0 cn 2) 6 1 10 (5 21n on on is an active flotation reagent for columbium minerals when used either in the formof the'chernicallypure analytical reagent or in a crude form obtained as an impure reaction product of a known procedure.

This has been demonstrated by numerous laboratory v tests, typified by those set forth herebelow:

COMPARATIVE TESTS AS BETWEEN PURE AND 7 w CRUDE REAGENT a In this series of tests, respective 1,000 gram charges of a low grade, carbonatite type, columbium .ore from the province of Quebec, Canada, containing less than 0.6 percent columbium oxide (Ch o in the form of the minerals pyrochlore, perovskite, and others not yet definitely identified nor classified but believed to include A at least both niocalite and betafite, were ground to 90 percent minus 200 mesh. They were carefully deslimed, and were individually conditioned with the quantity of the reagent specified in the following tabulated test data and with 20 drops (0.6 gram) of burner oil, i. e. do-

. mestic fuel oil, for approximately one minute; They mixing 5 grains of o-nitrophenol, 8.3 grams of o-aminophenol, and 18 grams of glycerol in a 500 ml. flask, and

slowly adding 8.2 ml. of concentrated H the flask being fitted With a reflux condenser, and the mixture being boiled gently for five hours. Following cooling,

the resulting solution was dilutedto a volume of 250 m1.

e e -Reame wnce mt Weight, Chaos, Recov- Beagcnt percent percent ery, per- 7 cent (1) 2 g. o. P. 8-quinollnol ass 1. 49 90. s .(2) 60 ml. crude 8 guinolh1ol so1utlon 33.0 1.56 84.5 (3) 80 crude 8-qliiriolinolsolutionn 44.0 1. 37 93. 9 (4) 80 -ml. crude S-quinblinol solution I (reflux time 10 hours. 39. 7 l. 18 90.7

We have also found that reagent consumption can be reduced by treating the ore for removal .of various gangue minerals prior to flotation for recovery of the columbium minerals. A typical test is reported herebelow:

PRELIMINARY UPGRADING BY REMOVAL OF 1 GANGUE CONSTITUENTS This was a locked cyclic test, wherein, for each cycle, variousgangue constituents were removed by conventional techniques indicatedin the optional portion of the flow sheet of the accompanying drawing.

A charge of 4,000 grams .of the same carbonatite type, columbiurn ore was prepared for each cycle as in the foregoing tests, and was made into an aqueous pulp in accordance with conventional practice. Such aqueous pulp was subjected to flotation with a fatty acid collector reagent to remove calcite and apatite. The froth conccntrate was passed to Waste, and the tailings were subiected to, sulfideflotation utilizing a sulfonated petroleum oil'and a xanthate collector as reagents. The froth concentrate was passed to waste, and the tailings subjected to magnetic separation for the removal of magnetite.

The resulting upgraded ore pulp (from 0.6 percent Cb O to 2.36 percent Cb O was deslimed, and the deslimed pulp conditioned with 2 grams of C. P. 8-quinolinol and 1.5 grams of burner oil for flotation.

Agitation and aeration of the so conditioned pulp in a laboratory flotation machine resulted in a columbiumbearing froth, which was cleaned twice by further flotation of the same character. The cleaner tailings were added to the subsequent batch of ore pulp in accordance with'closed cycle practice. The metallurgical results were as follows:

Weight OM05, Dlstripercent percent bution, percent RECOVERY OF REAGENT-BEARING SOLUTION For this cyclic test, 1,000 gram batches of the same carbonatite type, eolumbium ore, prepared as in the foregoing tests, were deslimed .and upgraded by the aforedescribed mica and iron sulfide flotation and by removal of magnetite. In this instance, the pulp was not treated for removal of calcite andapatite.

The upgraded ore pulp was filtered, and the filter cake was used in the preparation of the aqueous pulp for the colu nbium flotation. The solution employed for this repulping operation was prepared initially from crude reagent obtained in the same manner as for the first series of tests, although, here, the reflux time was ten hours 4 (as in the touch o the iorego g t instead of five Six liters of solution were prepared from 150 ml. of the crude reagent. This supplied all dilution and wash water used during the flotation procedure, as well as the aqueous phase of the flotation pulp.

Agitation and aeration of the reagent-bearing pulp resulted in a columbium-bearing froth concentrate. The froth and tailings were separately filtered, and the respective filtrates were returned to the original solution. An additional 25 ml. of crude reagent was then added to the lt t O l, n the procedure was repeated.

In all, the procedure was carried out a total of six times. The recovery and grade of concentrates from the sixth cycle (after equilibrium was achieved) are tabulated as follows:

Rougher concentrate The difference in reagent consumption between the straight flotation process using 8-.quinolinol as a reagent and the more preferred practice of upgrading prior to flotation, coupled with recycling the liquid phase of the tailings and froth concentrate from the 8-quinolinol flotae tion, is well demonstrated by comparing Test No. 4 of the first series of tests with the last test above. It will be seen that comparable recovery was made in the latter instance with on y v25 n l. oi he crude reagent solution as compared with ml, for the former.

In the course of our work, many flotation tests were mad usin v r us conventio al eage ts n an ff rt t float col mbium m n ra sr; non f these yi ded e onom co y- A o in ly, n omparative tests as between the reagent here disclosed and other reagents are presented.

Our. tests have shown that the 8-quinolinol reagent, wh h n hemic l y p or crude rm, s effective in acid neutral, .or basic pulps. In such tests, however, recovery has fallen 01? considerably in the extremes of pH range. Accordingly, it is preferred that this flotation process be carried out with a near neutral pulp.

The 8-.quinolinol reagent has proven to have natural frothiug properties, which makes it unnecessary to add any other frothing reagent in many instances in which the process is used. It should be kept in mind, however, that the natural frothing properties may be supplemented wherever found desirable by addition of a conventional frothing agent, such as pine oil.

We have conducted tests on many difierent types of ores containing a variety of colurnbium minerals. These tests indicate that our process is effective on columbium minerals in general.

The following examples detail representative tests showing ratios of concentration of 1 to 12.1, 1 to 41.7,

and 1 to 9.5, respectively:

' EXAMPLE NO. 1

Two thousand grams of the carbonatite-type ore utilized in the previous tests were ground to approximately percent minus 200 mesh, deslimed, the iron sulfide minerals removed from the ore pulp by flotation using xanthate collector, and the magnetite removed magnetically. The ore pulp was then filtered, split into two equal parts, and each part was individually re-pulped in a laboratory flotation machine,.conditioned with 2.5 grams of 8-quinolinol, and afroth concentrate recovered. The tailings were combined for assay, and the froth concentrates were combined, conditioned with 0.5 gram of 8- quinolinol, and a froth concentrate recovered by flotation. The concentrate was then recleaned three times by flotation, using the solution recovered (by filtration) from the tailings of the previous step for dilution water.

Test results Weight, onto, Distri- Product percent percent butlon,

' percent- Concentrate 8. 24 6. 60 81. 84

CalculatedHeadlng 100.00 0.66 100.00

EXAJVEPLE NO. 2

One thousand grams of a pyrochlore-bearing granite from Nigeria were ground at 67 percent solids for twentythree minutes in a laboratory ball mill. The resultant pulp was deslimed, filtered, re/pulped ina laboratory flotation machine, conditioned with four grams of 8- quinolinol, and a froth concentrate removed. The froth concentrate was cleaned twice by flotation.

Weight, 0e20,, Distri- Product percent percent button,

percent Rougher Talllng 73. 83 0. 06 21. 93 1st Cleaner Taillng- 16. 21 0. 15. 25 2nd Cleaner Taillng.- 7. 56 0. 33 12.33 Concentrate 2. 40 4. 25 50. 49

Calculated Heading 100. 00 0. 100. 00

It will be obvious that various other elements, such as uranium, that are intimately associated with the columbium minerals will also be recovered by this process.

Comparative tests have been carried out, as follows:

Test No. 1 (8-quin0linol) Five hundred grams of a low grade carbonate type ore containing the columbium minerals Pyrochlore and Perovs kite and upgraded by removal of calcite and apatite, by desliming, and by removal of iron sulfide and magnetite were subjected to a batch flotation procedure involving flotation at pH 7.2 to 8.0 for ten minutes in the presence of two and one-half grams of 8-quinolinol. The rougher froth concentrate obtained was cleaned by reflotation, with the following results:

' Weight, 011205, Distri- Product percent percent butlon, percent Cleaner Concentrate 4. 74 10. 36 31.00 Cleaner Talllng 22.35 3.39 47.83 Rougher Taillng.. 72. 91 0. 46 21. 17

Calculated Feed 100. 00 1. 58 100. 00

Test No.2 (2- mefltyl-8-quinolin0l) 1 The procedure here was identical with that of the foregoing test, except 3.5 grams of Z-methyI-B-quinolinol (8- hydroxyquinaldine) wereused as the collector reagent; Results were as follows: r

' Weight, CD205, DlStli- Product percent percent button,

. percent Cleaner Concentrate 60 9. 21 30.82 Cleaner Talllng 24. 68 4. 07 40. 90 Rougher Tailing 68. 72 0.53 18. 28

Calculated Feed 100. 00 1. 98 100. 00

Test No. 3 (4-methyl-8- quinolinol)' The procedure here was identical with the foregoing tests, except 2.0 grams of4-methyl-8-quinolinol were used as the collector reagent. Results were as follows:

7 Weight, 05.0,, Distri- Product percent percent butlon,

percent Recleaner Concentrate 3. 18 19. 3 34. 70 Recleaner Telling 7. 01 5. 24 20. 77 Cleaner Talllng 43. 10 l. 60 38. 99 Rougher Talllng 46. 71 0. 21 5. 54

Test N0. 4 (6-methyl-8-quirtolinol) The procedure here was identical with the foregoing tests, except 2.0 grams of 6-methyl-8-quinolinol were used as the collector reagent. Results were as follows:

Of the several reagents used in the above series of tests, only S-quinolinol is readily available. It was possible to purchase the reagent for Test No. 2 from Eastman Kodak Company, but the reagents for Tests No. 3 and 4 were synthesized in the laboratory.

This application constitutes a continuation-in-part of our copending application Serial Number 612,849, filed Sept. 28, 1956, entitled Process of Concentrating Niobium Minerals by Froth Flotation, which has been found to be allowable but which has been abandoned in favor of the present application.

We claim:

1. In a process of froth flotation for the separation of columbium minerals from other constituents of a columbium ore, the steps of agitating and aerating an aqueous pulp containing said columbium ore and 8- quinolinol, the latter serving as a collector reagent selective to columbium minerals; and recovering the resulting froth as a columbium concentrate.

2. The process of claim 1, wherein the said steps are preceded by pro-concentration treatment of an aqueous pulp of the ore.

3. The process of claim 2, wherein the procedure is carried out on a cyclic basis, and, following the said steps of each cycle, at least the tailings are treated for recovery of their reagent-bearing liquid phase; wherein the upgraded pulp is treated for removal of its liquid phase; and wherein the solid phase of said upgraded pulp is re-pulped with the recovered reagent-bearing liquid phase.

4. The process of claim 3, wherein the 8-quinolinol is an impure reaction product.

5, The process of claim 1,, wherein 'alsocontains-a neutral petroleum oil. H 7 v 6. The process of claim 1, wherein the S-quinolinol isv an impure reaction product.

'7. The process of claim 1, wherein at least the tailings resulting from the said steps are'treated for recovery of their reagent-bearing liquid phase; and wherein the said'liquid phase is used in pulping additional ore for said process. a

I 8. The process of claim 1, wherein the said steps are preceded by flotation of sulfide minerals from an aqueous pulp of the ore, for upgrading said ore.

9. In a process of froth flotation for the separation of columbium minerals from other constituents of a columbium ore, the steps of agitating and aerating an aqueous pulp containing said columbium ore and a collector reagent selected from'the group consisting of 8- quinolinol and mono-lower-alkyl-substituted 8-quinolinols; and recovering the resulting froth as a columbium concentrate.

10. The process of claim 9, wherein the said steps are preceded by pre-concentration treatment of an aqueous pulp of the ore.

the aqueous pulp r 8 i '11. .The process of clairnlO, wherein the procedure is carried out on acyclic basis, and, following the said steps of each cycle, at least the tailings are treated for recovery of their reagent-bearingliquid phase; wherein 'the upgraded pulp is treated for removal ofitsliquid i in the said liquid phase is used in pulping additional ore for said process.

14. The process of claim 9, wherein the said steps are preceded by flotation of sulfide minerals from an aqueous pulp of the ore, for upgrading said ore.

References Cited in the file of this patent Oxine and Its Derivatives, Hollingshead, vol. II, 594- 596, 1954. 

1. IN A PROCESS OF FROTH FLOTATION FOR THE SEPARATION COLUMBIUM MINERALS FROM OTHER CONSTITUENTS OF A COLUMBIUM ORE, THE STEPS OF AGITATING AND AERATING AN AQUEOUS PULP CONTAINING SAID COLUMBIUM ORE AND 8QUINOLINOL, THE LATTER SERVING AS A COLLECTOR REAGENT SELECTIVE TO COLUMBIUM MINERALS; AND RECOVERING THE RESULTING FROTH AS A COLUMBIUM CONCENTRATE. 